1. Field of the Invention
This invention relates generally to ice makers, and more particularly, to an improved ice maker for use in domestic refrigerators and the like.
2. Description of Background Art
In one form of an ice maker, an ice mold and associated mechanism are mounted in the freezer compartment of a domestic refrigerator/freezer apparatus. One example of such an ice maker is illustrated in Linstromberg, U.S. Pat. No. 3,276,225, which is owned by the assignee of the present invention. Such ice makers are provided with resistance heaters for heating the mold upon completion of the forming of the ice bodies therein so as to permit freeing of the ice bodies therefrom for dispensing automatically to a subjacent collecting bin. A thermostat in heat transfer association with the mold senses when the ice bodies are sufficiently frozen and thereafter initiates an ejection cycle. During the ejection cycle, ejector blades move through the cavities in which the ice bodies are formed to force the ice bodies therefrom for delivery to the bin. The cycle is completed after the mold warms up to a temperature sufficient to allow for resetting of the thermostat. As described in the Linstromberg patent, the ejector must rotate two complete revolutions in the cycle in order to allow for sufficient time for the mold to warm up to reset the thermostat. The resistance heater remains energized for the entire time.
As a result of the ejector going through two complete revolutions, the total cycle time of harvesting ice is increased. Since the heater remains on for most of the cycle time, a greater time is required for a subsequent batch of ice to be made as the heater causes the mold to be at an elevated temperature on the order of 80.degree. to 100.degree. F. Also, the electrical and mechanical components are subject to additional stress due to the need for two complete revolutions.
Another type of ice maker is described in Andersson, U.S. Pat. No. 2,717,501 wherein an ejector must pass through only a single revolution in the ice harvesting cycle. Here again, however, a heater is energized via a first thermostat immediately at the start of the harvesting cycle and remains energized throughout the entire cycle. A second thermostat acts as a high temperature switch to shut off the heater if the control malfunctions. It is believed that the heater is energized for the full cycle in order to reset the thermostat. The heater being energized for the full cycle causes the mold to be at an elevated temperature, increasing ice making time and decreasing reliability of components therein, as described above.
The present invention overcomes the above problems of prior art ice makers in a novel and simple manner.